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Very cool project. I wonder if compressed sensing would be useful here. In the paper they describe this custom (and seemingly ad-hoc) video compression algorit
by awelkie 9y ago
Very cool project.
I wonder if compressed sensing would be useful here. In the paper they describe this custom (and seemingly ad-hoc) video compression algorithm that is suitable for the low-power device. Basically, the camera averages blocks of pixels into "super pixels" all in the analog domain, sends these super pixels over the wireless link, and then the receiver can request the individual pixels of any super pixel that seems like it might have changed since the last frame. But with compressed sensing, can't all of this be done by sending random linear combinations of all pixel values (like the single pixel camera)? It seems like then you can avoid the bi-directional link and also get rate adaptation for free.
- awelkie 9y agoAlso, in the paper they say they used pulse-width modulation for the backscatter signal instead of just attaching the sensors directly to the antenna like the Great Seal Bug because the dynamic range of the photodiodes is much less than that of a microphone and they wanted to avoid using an amplifier (section 3.1 in the paper). But the PWM requires power as well. Would an amplifier that only has to map the range of a photodiode to the range of a microphone really require that much more power? And if so, are we talking like twice the power, 10x, 100x?